As is known, bolts, screws and retaining rings are normally used for locking and securing two or more coupling members.
Fastening systems of this sort invariably require special tools for installation and removal.
In aircraft applications, in which weight reduction is an important issue, they also have the drawback of requiring parts in addition to the coupling members. And, in some cases, as when screwing or bolting together cylindrical coupling members, these must be provided with annular flanges with holes for the screws and bolts.
Lastly, when using steel retaining rings cooperating with aluminium or magnesium coupling members, galvanically-induced corrosion phenomena may arise.